Chelsea Flower Show judge Andrew Wilson shares his crib sheet for
analysing gardens – how plants, hard materials, colour and layout work
together to create the whole.

Garden visiting has to be one of the most popular pastimes in Britain. But why? Is it the fresh air, the space for the children to roam, or the cream teas? Are we paying any attention to the garden at all, or is it ultimately just a pleasant backdrop to a good day out?

As a garden designer and a teacher of garden design, I know the thinking and organisation that goes into a good garden. Moreover, as a judge of show gardens for the RHS, I take part in a regular analysis of gardens that ultimately delivers a badge of excellence.

How does this analysis work without affecting one’s enjoyment of the garden? Well, here are a few pointers — a sort of judge tool kit that might help alert you to the formal qualities of the gardens you visit.

Background research

The same rules cannot be applied to every garden. A Capability Brown landscape is all about large-scale composition, sweeps of tree planting and bucolic panoramas. An Arts and Crafts garden, by contrast, is all about hedged compartments, restricted views and complex, often colour-based planting, usually quite separate from the surrounding landscape.

Common to all good gardens, however, is a sense of integrity or coherence that allows all the different elements to work together as a composition. A little background research into a garden’s creator, and the period in which the garden was developed or changed, can help you analyse how it works.

The role of movement

Analysis should start as soon as you enter a garden. The designer will have considered some sort of progress. This is known as sequential design, in which each of the spaces you encounter will be related to each other. The threshold or division between each space is an essential part of the overall composition, revealing views and allowing the garden and its various contrasts or characteristics to be read in a controlled way.

Arts and Crafts designers used hedges or walls to give structure and order to the garden. The result is often formal, introverted and controlling. In later Modernist gardens, hedges were used as sculptural blocks. They allowed spaces, planting and design ideas to flow together, creating a more dynamic but less defined landscape.

In the former, the pattern of the garden is clear, while in the latter the pattern has to be deciphered and the best views or planting combinations debated.

For the uninitiated this can be confusing and in some cases irritating. For example, there is no point visiting Frederick Gibberd’s garden, Marsh Lane, near Harlow, if you are looking for refreshing flower planting, because there is very little. This does not make it a bad garden, merely a different one. It emerges invisibly from its surroundings and creates mysterious spaces around its many sculptures, full of atmospheric spirit.

Materials and structure

The choice of materials will tie a composition together. The classic approach is to use locally sourced stone or brick. Edwardian architect and garden designer Edwin Lutyens was a dab hand at this, which allows his greatest gardens to nestle into their wider context so beautifully.

Other gardens will use imported materials. This is more often the case in urban settings, where local character can be lost in the mêlée of cosmopolitan life. Many visitors simply say “I don’t like that”, when faced with innovation. This is their prerogative, of course, but can suggest a lack of wider thinking. Materials are usually chosen for a reason: to link with an overall concept or idea, or they may have been salvaged and available for free. Why not discuss this with the owner or gardener and find out more?

Planting design

Many gardens are little more than collections of plants. These can indeed be objects of wonder but, strangely, few plant collections are well designed. Design is about coherence and consistency, structure and the integration of ideas, so we need to look at how plants relate together.

Again, there is room for great variety here. The ecological planting of the London Wetland Centre, in Barnes, for example, has a very different philosophy to the decorative splendour of Sissinghurst.

There is great promise in the work of our leading university researchers (the “Sheffield School”) yet little finds its way into the gardens we visit. James Hitchmough’s prairie planting at Wisley is tucked away in the furthest recess of the garden, whilst many a planting travesty is given pride of place elsewhere.

Creative plant choices

Look at why plants are being used in specific locations. Avenues and borders are generally clear and distinct entities but individual plant specimens and island beds can be much more ambiguous, often plonked in spare spaces without much thought.

The new ornamental meadow plantings favoured by contemporary designers such as Tom Stuart Smith or Piet Oudolf bring a different character again. These wide expanses of low perennials and grasses can be walked through rather than simply looked at, as we do with the traditional border.

Within any planting scheme look for the relationships that have brought different species together. They may be led by colour, texture or foliage shape. Certain forms or specific plants may be repeated many times in order to create rhythm and coherence.

Consider the scale of a planting scheme and ask questions about the depth of the planting area, the density of planting or the number of plants grouped together to achieve impact. I ask my students to make notes on selected plant groupings and to photograph them from many angles to enable them to understand the composition three-dimensionally.

A notebook, camera and a retractable tape measure are the tools of good garden analysis.

It’s all about space

Finally, there is a much more abstract way of analysing and reviewing gardens, which is to consider the relationship of what is known as mass and void. Mass is anything solid or that has volume. This includes planting, hedges, trees and buildings. The void is the empty space: lawns, paving and water. A quick assessment of the ratio of one to the other can produce an effective analysis of whether garden spaces work. A mass rating of 20-40 per cent generally creates a comfortable and interesting space. Gardens with less than 20 per cent mass, where the void is more dominant, may feel uncomfortable and somewhat sterile.

These are the key elements on my marking sheets when I’m teaching, or in conversation with other judges about a show garden.

While the system helps us to achieve as objective a response as possible, it isn’t the whole story. To any garden that we visit, we bring our preferences and our foibles. Some gardens will proclaim their character, intoxicating us with their charm. Others will leave us cold and uninspired. Sometimes it may be nothing more than the weather, or the time of year, that affects the impression a garden leaves.

Our reactions to a garden ultimately say more about us than about the gardens. Recognising this is the basis of all debate, and where the fun really starts.

Andrew Wilson is a garden designer and co-director of the Wilson McWilliam Studio, wmstudio.co.uk, a director of the London College of Garden Design, lcgd.org.uk, an author and a judge for show gardens for the Royal Horticultural Society.